A stator blade ring of an axial-flow, compressor includes a plurality of, for example, several ten to several hundred stator blades arranged in a circumferential direction.
A conventionally often used method of assembling a stator blade ring is to circumferentially perform electron beam welding from side surfaces of an inner shroud and an outer shroud that form a cabin wall, with a stator blade being inserted between the inner shroud and the outer shroud and temporarily assembled, to join opposite ends of the stator blade and the inner shroud and the outer shroud (see Patent Documents 1 and 2).    Patent Document 1: Japanese Patent Publication No. 58-57276    Patent Document 2: Japanese Patent Publication No. 59-2761